North America
North America is a continent entirely within the Northern Hemisphere and almost all within the Western Hemisphere. It is also considered by some to be a northern subcontinent of the Americas. It is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the west and south by the Pacific Ocean, and to the southeast by South America and the Caribbean Sea. North America covers an area of about 24,709,000 square kilometers (9,540,000 square miles), about 16.5% of the earth's land area and about 4.8% of its total surface. North America is the third largest continent by area, following Asia and Africa, and the fourth by population after Asia, Africa, and Europe. In 2013, its population was estimated at nearly 579 million people in 23 independent states, or about 7.5% of the world's population, if nearby islands (most notably the Caribbean) are included. North America was reached by its first human populations during the last glacial period, via crossing the Bering land bridge approximately 40,000 to 17,000 years ago. The so-called Paleo-Indian period is taken to have lasted until about 10,000 years ago (the beginning of the Archaic or Meso-Indian period). The Classic stage spans roughly the 6th to 13th centuries. The Pre-Columbian era ended in 1492, with the beginning of the transatlantic migrations—the arrival of European settlers during the Age of Discovery and the Early Modern period. Present-day cultural and ethnic patterns reflect interactions between European colonists, indigenous peoples, African slaves and their descendants. Owing to Europe's colonization of the Americas, most North Americans speak European languages such as English, Spanish or French, and their states' cultures commonly reflect Western traditions. The Americas are usually accepted as having been named after the Italian explorer Amerigo Vespucci by the German cartographers Martin Waldseemüller and Matthias Ringmann. Vespucci, who explored South America between 1497 and 1502, was the first European to suggest that the Americas were not the East Indies, but a different landmass previously unknown by Europeans. In 1507, Waldseemüller produced a world map, in which he placed the word "America" on the continent of South America, in the middle of what is today Brazil. He explained the rationale for the name in the accompanying book Cosmographiae Introductio: ... ab Americo inventore ... quasi Americi terram sive Americam (from Americus the discoverer ... as if it were the land of Americus, thus America). For Waldseemüller, no one should object to the naming of the land after its discoverer. He used the Latinized version of Vespucci's name (Americus Vespucius), but in its feminine form "America", following the examples of "Europa", "Asia" and "Africa". Later, other mapmakers extended the name America to the northern continent, In 1538, Gerard Mercator used America on his map of the world for all the Western Hemisphere. Some argue that because the convention is to use the surname for naming discoveries (except in the case of royalty), the derivation from "Amerigo Vespucci" could be put in question. In 1874, Thomas Belt proposed a derivation from the Amerrique mountains of Central America; the next year, Jules Marcou suggested that the name of the mountain range stemmed from indigenous American languages. Marcou corresponded with Augustus Le Plongeon, who wrote: "The name AMERICA or AMERRIQUE in the Mayan language means, a country of perpetually strong wind, or the Land of the Wind, and ... the The United Nations formally recognizes "North America" as comprising three areas: Northern America, Central America, and The Caribbean. This has been formally defined by the UN Statistics Division. "Northern America", as a term distinct from "North America", excludes Central America, which itself may or may not include Mexico (see Central America § Different definitions). In the limited context of the North American Free Trade Agreement, the term covers Canada, the United States, and Mexico, which are the three signatories of that treaty. France, Italy, Portugal, Spain, Romania, Greece, and the countries of Latin America use a six-continent model, with the Americas viewed as a single continent and North America designating a subcontinent comprising Canada, the United States, and Mexico, and often Greenland, Saint Pierre et Miquelon, and Bermuda. North America has been historically referred to by other names. Spanish North America (New Spain) was often referred to as Northern America, and this was the first official name given to Mexico. Regions Geographically the North American continent has many regions and subregions. These include cultural, economic, and geographic regions. Economic regions included those formed by trade blocs, such as the North American Trade Agreement bloc and Central American Trade Agreement. Linguistically and culturally, the continent could be divided into Anglo-America and Latin America. Anglo-America includes most of Northern America, Belize, and Caribbean islands with English-speaking populations (though sub-national entities, such as Louisiana and Quebec, have large Francophone populations; in Quebec, French is the sole official language ). Laurentia is an ancient craton which forms the geologic core of North America; it formed between 1.5 and 1.0 billion years ago during the Proterozoic eon. The Canadian Shield is the largest exposure of this craton. From the Late Paleozoic to Early Mesozoic eras, North America was joined with the other modern-day continents as part of the supercontinent Pangaea, with Eurasia to its east. One of the results of the formation of Pangaea was the Appalachian Mountains, which formed some 480 million years ago, making it among the oldest mountain ranges in the world. When Pangaea began to rift around 200 million years ago, North America became part of Laurasia, before it separated from Eurasia as its own continent during the mid-Cretaceous period. The Rockies and other western mountain ranges began forming around this time from a period of mountain building called the Laramide orogeny, between 80 and 55 million years ago. The formation of the Isthmus of Panama that connected the continent to South America arguably occurred approximately 12 to 15 million years ago, and the Great Lakes (as well as many other northern freshwater lakes and rivers) were carved by receding glaciers about 10,000 years ago. North America is the source of much of what humanity knows about geologic time periods. The geographic area that would later become the United States has been the source of more varieties of dinosaurs than any other modern country. According to paleontologist Peter Dodson, this is primarily due to stratigraphy, climate and geography, human resources, and history. Much of the Mesozoic Era is represented by exposed outcrops in the many arid regions of the continent. The most significant Late Jurassic dinosaur-bearing fossil deposit in North America is the Morrison Formation of the western United States. North America occupies the northern portion of the landmass generally referred to as the New World, the Western Hemisphere, the Americas, or simply America (which, less commonly, is considered by some as a single continent with North America a subcontinent). North America's only land connection to South America is at the Isthmus of Darian/ Isthmus of Panama. The continent is delimited on the southeast by most geographers at the Darién watershed along the Colombia-Panama border, placing almost all of Panama within North America. Alternatively, some geologists physiographically locate its southern limit at the Isthmus of Tehuantepec, Mexico, with Central America extending southeastward to South America from this point. The Caribbean islands, or West Indies, are considered part of North America. The continental coastline is long and irregular. The Gulf of Mexico is the largest body of water indenting the continent, followed by Hudson Bay. Others include the Gulf of Saint Lawrence and the Gulf of California. Before the Central American isthmus formed, the region had been underwater. The islands of the West Indies delineate a submerged former land bridge, which had connected North and South America via what are now Florida and Venezuela. There are numerous islands off the continent's coasts; principally, the Arctic Archipelago, the Bahamas, Turks & Caicos, the Greater and Lesser Antilles, the Aleutian Islands (some of which are in the Eastern Hemisphere proper), the Alexander Archipelago, the many thousand islands of the British Columbia Coast, and Newfoundland. Greenland, a self-governing Danish island, and the world's largest, is on the same tectonic plate (the North American Plate) and is part of North America geographically. In a geologic sense, Bermuda is not part of the Americas, but an oceanic island which was formed on the fissure of the Mid-Atlantic Ridge over 100 million years ago. The nearest landmass to it is Cape Hatteras, North Carolina. Canadian geology Geologically, Canada is one of the oldest regions in the world, with more than half of the region consisting of precambrian rocks that have been above sea level since the beginning of the Palaeozoic era. Canada's mineral resources are diverse and extensive. Across the Canadian Shield and in the north there are large iron, nickel, zinc, copper, gold, lead, molybdenum, and uranium reserves. Large diamond concentrations have been recently developed in the Arctic, making Canada one of the world's largest producers. Throughout the Shield there are many mining towns extracting these minerals. The largest, and best known, is Sudbury, Ontario. Sudbury is an exception to the normal process of forming minerals in the Shield since there is significant evidence that the Sudbury Basin is an ancient meteorite impact crater. The nearby, but less known Temagami Magnetic Anomaly has striking similarities to the Sudbury Basin. Its magnetic anomalies are very similar to the Sudbury Basin, and so it could be a second metal-rich impact crater. The Shield is also covered by vast boreal forests that support an important logging industry. United States geology The lower 48 US states can be divided into roughly five physiographic provinces: 1. The American cordillera 2. The Canadian Shield Northern portion of the upper midwestern United States. 3. The stable platform 4. The coastal plain 5. The Appalachian orogenic belt The geology of Alaska is typical of that of the cordillera, while the major islands of Hawaii consist of Neogene North America is a very large continent which surpasses the Arctic Circle, and the Tropic of Cancer. Greenland, along with the Canadian Shield, is tundra with average temperatures ranging from 10 to 20 °C (50 to 68 °F), but central Greenland is composed of a very large ice sheet. This tundra radiates throughout Canada, but its border ends near the Rocky Mountains (but still contains Alaska) and at the end of the Canadian Shield, near the Great Lakes. Climate west of the Cascades is described as being a temperate weather with average precipitation 20 inches (510 mm). Climate in coastal California is described to be Mediterranean, with average temperatures in cities like San Francisco ranging from 57 to 70 °F (14 to 21 °C) over the course of the year. Stretching from the East Coast to eastern North Dakota, and stretching down to Kansas, is the continental-humid climate featuring intense seasons, with a large amount of annual precipitation, with places like New York City averaging 50 inches (1,300 mm). Starting at the southern border of the continental-humid climate and stretching to the Gulf of Mexico (whilst encompassing the eastern half of Texas) is the subtropical climate. This area has the wettest cities in the contiguous U.S. with annual precipitation reaching 67 inches (1,700 mm) in Mobile, Alabama. Stretching from the borders of the continental humid and subtropical climates, and going west to the Cascades Sierra Nevada, south to the southern tip of durango, north to the border with tundra climate, the steppe/desert climate is the driest climate in the U.S. Highland climates cut from north to south of the continent, where subtropical or temperate climates occur just below the tropics, as in central Mexico and Guatemala. Tropical climates appear in the island regions and in the subcontinent's bottleneck. Usually of the savannah type, with rains and high temperatures constants the whole year. Found in countries and states bathed by the Caribbean Sea. Notable North American fauna include the bison, black bear, prairie dog, turkey, pronghorn, raccoon, coyote and monarch butterfly. Notable plants that were domesticated in North America include tobacco, maize, squash, tomato, sunflower, blueberry, avocado, cotton, chile pepper and vanilla. [[Category:Continents] Category:America